U.S. patent number 10,393,554 [Application Number 15/019,260] was granted by the patent office on 2019-08-27 for security system having a magnetic displacement sensor system and analytics system.
This patent grant is currently assigned to SENSORMATIC ELECTRONICS, LLC. The grantee listed for this patent is Sensormatic Electronics, LLC. Invention is credited to Richard John Campero, Miguel Galvez.
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United States Patent |
10,393,554 |
Campero , et al. |
August 27, 2019 |
**Please see images for:
( Certificate of Correction ) ** |
Security system having a magnetic displacement sensor system and
analytics system
Abstract
A security system having a magnetic displacement sensor system
and an analytics system. The magnetic displacement sensor system
includes a displacement sensor for detecting a magnetic field
strength from a magnet. The analytics system determines a status of
the magnetic displacement sensor system based on a comparison of
the detected magnetic field strength and a profile for the magnetic
displacement sensor system.
Inventors: |
Campero; Richard John (Gilroy,
CA), Galvez; Miguel (Salem, NH) |
Applicant: |
Name |
City |
State |
Country |
Type |
Sensormatic Electronics, LLC |
Boca Raton |
FL |
US |
|
|
Assignee: |
SENSORMATIC ELECTRONICS, LLC
(Boca Raton, FL)
|
Family
ID: |
59496180 |
Appl.
No.: |
15/019,260 |
Filed: |
February 9, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170227386 A1 |
Aug 10, 2017 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G08B
25/14 (20130101); G01D 5/12 (20130101); G08B
13/08 (20130101); G08B 29/18 (20130101); G01D
18/00 (20130101); G01D 5/145 (20130101) |
Current International
Class: |
G01D
18/00 (20060101); G01D 5/12 (20060101); G08B
13/08 (20060101) |
Field of
Search: |
;324/200,207.11-207.15,211,220,233,500,529,530,234-247,160,177,169,139,765.01 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Maxim Guidelines for Reliable Long Line 1-Wire Networks Tutorial.
http://www.maximintegrated.com/en/app-notes/index.mvp/id/148,
downloaded Dec. 29, 2015. Twenty-two pages. cited by applicant
.
"Using techBASIC to Turn Your iPhone or iPad into a Metal
Detector," techBlog,
http://www.byteworks.us/Byte_Works/Blog/Entries/2011/11/30. Nov.
30, 2011, Byte Works, Inc. Six pages. cited by applicant .
Xtrinsic MAG3110 Magnetometer, freescale.com/magnetic. 2010-2014,
Freescale Semiconductor, Inc. Two pages. cited by
applicant.
|
Primary Examiner: Koval; Melissa J
Assistant Examiner: Nguyen; Trung
Attorney, Agent or Firm: Arent Fox LLP
Claims
What is claimed is:
1. A security system, comprising: a magnetic displacement sensor
system including a displacement sensor for detecting magnetic field
strengths from a magnet over a time period and identifying an event
based on the magnetic field strengths over the time period; and an
analytics system in communication with the magnetic displacement
sensor system and comprising: an analytics database storing one or
more event profiles for the magnetic displacement sensor system,
each event profile including magnetic field strength changes and a
represented event represented thereby; and an analytics engine for
determining a status indicative of a validity of data received from
the magnetic displacement sensor system based on a comparison of
the magnetic field strengths and an event profile stored in the
analytics database in association with the event for the magnetic
displacement sensor system.
2. The security system according to claim 1, wherein the analytics
engine updates the event profile based on the magnetic field
strengths.
3. The security system according to claim 1, wherein the analytics
system is integrated within a system control panel.
4. The security system according to claim 1, wherein the analytics
system is implemented as a cloud-based system comprising multiple
profiles stored in the analytics database for each client.
5. The security system according to claim 1, wherein the event
profile is a time normalized profile, an open slow profile, a
closed slow profile, an open fast profile, a closed fast profile, a
secured state profile, or an unsecured state profile.
6. The security system according to claim 1, wherein the status is
a normal status, a damaged sensor status, a disconnected sensor
status, or a predictive failure status.
7. The security system according to claim 1, wherein the magnetic
displacement sensor system comprises a 3-axis magnetometer having a
detection stage for detecting the magnetic field strengths along an
x-axis, a y-axis, and a z-axis.
8. The security system according to claim 7, wherein the
displacement sensor comprises a controller for reading the magnetic
field strengths from the 3-axis magnetometer and determining if the
magnetic field strengths indicate the event.
9. The security system according to claim 8, wherein the controller
comprises a buffer for storing the magnetic field strengths.
10. The security system according to claim 8, wherein the 3-axis
magnetometer and the controller are integrated on a single
chip.
11. The security system according to claim 1, wherein the
displacement sensor is powered by a battery and the displacement
sensor comprises a parasitic power-harvesting circuit for charging
the battery.
12. The security system according to claim 1, further comprising a
system control panel for powering the displacement sensor via a
network.
13. A method for assessing a status of a magnetic displacement
sensor system, comprising: detecting, by the magnetic displacement
sensor system, magnetic field strengths from a magnet over a time
period; determining if the magnetic field strengths over the time
period indicate an event; sending the event including the magnetic
field strengths to an analytics system; comparing, by an analytics
engine of the analytics system, the magnetic field strengths to an
event profile stored in an analytics database of the analytics
system in association with the event for the magnetic displacement
sensor system, the analytics database storing one or more event
profiles for the magnetic displacement sensor system, each profile
including magnetic field strength changes and a represented event
represented thereby; and determining the status indicative of a
validity of data received from the magnetic displacement sensor
system based on the comparing.
14. The method according to claim 13, wherein the status is a
normal status, a damaged sensor status, a disconnected sensor
status, or a predictive failure status.
15. The method according to claim 13, further comprising
determining, by the analytics engine, that the event is an opening
type of event or a closing type of event.
16. The method according to claim 13, further comprising
normalizing, by the analytics engine, a time axis for the event
profile.
17. The method according to claim 13, further comprising
dynamically updating, by the analytics engine, the event profile
based on receipt of multiple events from the magnetic displacement
sensor system over time.
18. The method according to claim 13, wherein the event profile is
a time normalized profile, an open slow profile, a closed slow
profile, an open fast profile, a closed fast profile, a secured
state profile, or an unsecured state profile.
19. The method according to claim 13, further comprising:
generating, by the analytics engine, a diagnostic assessment based
on the status of the magnetic displacement sensor system; sending,
by the analytics engine, the diagnostic assessment to a system
control panel; and notifying, by the system control panel, a user
of necessary repairs based on the diagnostic assessment.
20. A magnetic displacement sensor system, comprising: a magnet
mounted to a window or a door; and a magnetic displacement sensor
comprising: an interface in communication with a network; a
magnetometer for detecting magnetic field strengths from the magnet
over a time period; and a controller for reading the magnetic field
strengths from the magnetometer and determining if the magnetic
field strengths over the time period indicate an event, wherein the
controller sends the event, including the magnetic field strengths,
to an analytics system via the interface, the analytics system
comprising an analytics engine and an analytics database storing
one or more event profiles for the magnetic displacement sensor,
each profile including magnetic field strength changes and a
represented event represented thereby, the analytics engine
determining a status indicative of a validity of data received from
the magnetic displacement sensor system based on a comparison of
the magnetic field strengths and an event profile stored in the
analytics database in association with the event for the magnetic
displacement sensor system.
21. An analytics system comprising: an analytics database storing
one or more event profiles for a magnetic displacement sensor
system, each event profile including magnetic field strength
changes and a represented event represented thereby; and an
analytics engine for: receiving magnetic field strengths detected
by the magnetic displacement sensor over a time period and an event
identified therefrom; and determining a status indicative of a
validity of data received from the magnetic displacement sensor
system based on a comparison of the magnetic field strengths and an
event profile stored in the analytics database in association with
the event for the magnetic displacement sensor system.
22. The security system according to claim 1, wherein the analytics
engine compares patterns associated with the magnetic field
strengths and the event profile.
23. The method according to claim 13, further comprising comparing,
by the analytics engine, patterns associated with the event and the
event profile.
Description
BACKGROUND OF THE INVENTION
Magnetic displacement sensor systems are a common subsystem in many
intrusion systems, and security systems more generally. Most often,
these magnetic displacement sensor systems are used to detect
whether doors or windows are ajar or secured. More generally,
however, magnetic displacement sensor systems can be used in other
applications that require proximity and/or end position sensing, or
moving part position sensing. In these intrusion/security systems,
the magnetic displacement sensor systems are typically monitored by
a system control panel via a network. In this way, the control
panel can monitor whether doors or windows are ajar, or secured,
for example.
The magnetic displacement sensor systems have traditionally
included magnets and reed switches. When the magnets, which are
usually installed on the moving parts, are brought into proximity
of the reed switches, which are usually installed on adjacent
portions of stationary parts, the contacts of switches are closed
and the switches are conductive. The control panels then monitor
the conductivity of the reed switches.
More recently, it has been proposed to use magnetometers in place
of the traditional reed switches. The magnetometers detect strength
of the magnetic field generated from the magnets. The corresponding
magnetic displacement sensors then determine whether the door, for
example, is ajar, or not, by determining whether the magnetic field
strength detected by the magnetometers are greater or less than a
threshold, which is typically established through a calibration
step.
SUMMARY OF THE INVENTION
Reed switch-based magnetic displacement sensor systems often
require maintenance. The reed switches themselves can break. The
magnets on the moving parts can become displaced such that there
may be insufficient magnetic field at the switch to close the
switch, even when the door is completely closed. Such displacement
can also result in intermittent failure. The magnetic field at the
switch may be just sufficient to close the switch but may open if
the switch or the door is merely bumped to thereby result in
transient operation.
The present invention relates to magnetic displacement sensor
systems that incorporate magnetometers. In examples, it concerns
the tracking of the behavior of the systems in order to determine
the status of the magnetic displacement sensor systems. As a
result, problems such as sensor damage or displacement or other
miscalibration can be assessed. This allows preventative
maintenance or simply determining the health of the sensor systems
to assess the validity of the data from them.
In general, according to one aspect, the invention features a
security system having a magnetic displacement sensor system and an
analytics system. The magnetic displacement sensor system includes
a displacement sensor for detecting a magnetic field strength from
a magnet. The analytics system determines a status of the magnetic
displacement sensor system based on a comparison of the detected
magnetic field strength and a profile for the magnetic displacement
sensor system.
There is a variety of statuses for the magnetic displacement sensor
system. Each status relates to a condition or a state of the
magnetic displacement sensor system. Example statuses can include a
normal status, a damaged sensor status, a displaced sensor status,
or a predictive failure status.
There are different rates (e.g., fast, close) at which a door or
window can be opened or closed. Example profiles (corresponding
with the door or window) for the magnetic displacement sensor
system can include: a time normalized profile, an open slow
profile, a closed slow profile, an open fast profile, a closed fast
profile, a secured state profile, or an unsecured state profile.
The analytics system can update these one or more profiles based on
detected magnetic field strengths received from the displacement
sensor over time.
The analytics system can be implemented locally or remotely with
respect to a system control panel. In one example, the analytics
system is implemented locally by integrating the analytics system
within the system control panel. In another example, the analytics
system is implemented remotely as a cloud-based system comprising
profiles stored in an analytics database for multiple clients.
The displacement sensor preferably includes a 3-axis magnetometer
having a detection stage for detecting the magnetic field strength
along an x-axis, a y-axis, and a z-axis.
The displacement sensor can further include a controller for
reading the magnetic field strength from the 3-axis magnetometer
and determining if the detected magnetic field strength indicates
an event. The controller preferably includes a buffer for storing
the read magnetic field strength.
The 3-axis magnetometer and the controller can be integrated on a
single chip.
The displacement sensor can be powered by different means. In one
example, the displacement sensor is powered by a battery and the
displacement sensor includes a parasitic power-harvesting circuit
for charging the battery. In another example, the security system
includes a system control panel for powering the displacement
sensor via a network.
In general, according to another aspect, the invention features a
method for determining a status of a magnetic displacement sensor
system. The method comprises a displacement sensor detecting a
magnetic field strength from a magnet. The displacement sensor
determines if the detected magnetic field strength indicates an
event. The displacement sensor sends the event including the
detected magnetic field strength to an analytics system. The
analytics system compares the event to an event profile for the
magnetic displacement sensor system. The analytics system
determines the status of the magnetic displacement sensor system
based on this comparison.
The method can include further steps for the analytics system. The
analytics system can determine whether the event is an opening type
of event or a closing type of event. The analytics system can
normalize a time axis for the event profile. The analytics system
can dynamically update the event profile based on receipt of
multiple events from the displacement sensor over time.
The analytics system can generate a diagnostic assessment based on
the determined status of the magnetic displacement sensor system.
The analytics system can send this diagnostic assessment to a
system control panel. The system control panel notifies a user of
necessary repairs based on the diagnostic assessment.
In general, according to another aspect, the invention features a
magnetic displacement sensor system having a magnet mounted to a
window or a door and a displacement sensor. The displacement sensor
includes an interface in communication with a network, a
magnetometer for detecting a magnetic field strength from the
magnet, and a controller for reading the magnetic field strength
from the magnetometer and determining if the detected magnetic
field strength indicates an event. The controller sends the event,
including the magnetic field strength, to a system control panel
via the interface.
In general, according to another aspect, the invention features a
security system that comprises a magnetic displacement sensor
system including a displacement sensor for detecting a magnetic
field strength from a magnet and an analytics system for
determining a status of the magnetic displacement sensor system
based on a comparison of the detected magnetic field strength and a
profile for the magnetic displacement sensor system.
In general, according to another aspect, the invention features an
analytics system that determines a status of magnetic displacement
sensor systems based on a comparison of the detected magnetic field
strength and a profile for the magnetic displacement sensor
systems.
The above and other features of the invention including various
novel details of construction and combinations of parts, and other
advantages, will now be more particularly described with reference
to the accompanying drawings and pointed out in the claims. It will
be understood that the particular method and device embodying the
invention are shown by way of illustration and not as a limitation
of the invention. The principles and features of this invention may
be employed in various and numerous embodiments without departing
from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, reference characters refer to the
same parts throughout the different views. The drawings are not
necessarily to scale; emphasis has instead been placed upon
illustrating the principles of the invention. Of the drawings:
FIG. 1 is a schematic diagram of a security system including a
magnetic displacement sensor system and an analytics system;
FIG. 2 is a schematic diagram of another security system including
the magnetic displacement sensor system and the analytics
system;
FIG. 3A is a detailed schematic view of the magnetic displacement
sensor system;
FIG. 3B is a detailed schematic view of another embodiment of the
magnetic displacement sensor system;
FIG. 4 is a detailed schematic view of a magnetometer of the
magnetic displacement sensor system;
FIGS. 5A-5B are magnetic field plots for a three axis magnetometer
when a door is opened and when the door is closed,
respectively;
FIGS. 6A-6B are magnetic field plots for a single axis magnetometer
when the door is opened and when the door is closed,
respectively;
FIG. 7 is a block diagram of the analytics system;
FIG. 8A is a flow chart illustrating a method of operation of the
magnetic displacement sensor system to process detected magnetic
field strength measurements;
FIG. 8B is a flow chart illustrating a method of training the
analytics system based on received magnetic field strength
measurements; and
FIG. 8C is a flow chart illustrating a method of operating the
analytics system with the magnetic displacement sensor system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention now will be described more fully hereinafter with
reference to the accompanying drawings, in which illustrative
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
As used herein, the term "and/or" includes any and all combinations
of one or more of the associated listed items. Further, the
singular forms and the articles "a", "an" and "the" are intended to
include the plural forms as well, unless expressly stated
otherwise. It will be further understood that the terms: includes,
comprises, including and/or comprising, when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
Further, it will be understood that when an element, including
component or subsystem, is referred to and/or shown as being
connected or coupled to another element, it can be directly
connected or coupled to the other element or intervening elements
may be present.
FIGS. 1 and 2 depict a security system 100 that includes magnetic
displacement sensor systems 240 and an analytics system 210 for
monitoring the magnetic displacement sensor systems 240. The
analytics system 210 determines a status for each magnetic
displacement sensor system 240 by monitoring their operation.
Each magnetic displacement sensor system 240 includes a
displacement sensor S and a magnet M. The displacement sensor S
detects a magnetic field strength experienced by the displacement
sensor S from the magnet. Thus, as the magnet M moves further from
the displacement sensor S, such as in the process of opening a
window, the displacement sensor S detects a decrease in the
magnetic field strength.
As illustrated, the magnetic displacement sensor systems 240 are
typically installed to detect whether doors and windows are ajar or
secured. Each displacement sensor S is usually mounted either on a
door frame 207 or on a window frame 208 and each magnet M is
mounted to the corresponding door 112 or window 113. As the door
112 is opened, the magnet M is moved away from the displacement
sensor S fixed on the door frame 207 causing the displacement
sensor S to measure a decrease in the magnetic field strength.
Similarly, as the window 113 is opened (e.g., sliding window 113
past an outer window 114 for a double-hung window), the magnet M is
moved away from the displacement sensor S fixed on the window frame
208 causing a decrease in magnetic field strength. As appreciated
by one of skill in the art, the magnetic displacement sensor
systems 240 can be used in other applications that require
proximity and/or end position sensing or moving part position
sensing.
The displacement sensors S are monitored and in some cases powered
by a system control panel 102. The system control panel 102
communicates with and powers the displacement sensor S via a safety
and security network 110 (e.g., microLAN). Specifically, the system
control panel 102 includes a line driver 103 that delivers power to
the safety and security network 110 for powering the displacement
sensors S. Also, the system control panel 102 includes a bus master
106 (e.g., 1-wire bus master) for providing communication with the
displacement sensors S on the safety and security network 110. The
system control panel 102 uses a panel controller 108 for
instructing the line driver 103 and the bus master 106 with respect
to providing communication and delivering power to the displacement
sensor S.
The displacement sensors S can be deployed on the safety and
security network 110 using a single bus or multiple buses. The
single bus can be implemented, for example, in the form of a linear
topology, a stubbed topology, or a star topology. The single bus
can include a 2-wire interface (e.g., 1-Wire.RTM. technology) that
allows for power and communication (i.e., data) to be supported on
the single bus. Alternatively, power and communication (i.e., data)
can be supported on multiple buses (e.g., separate power buses and
separate communication buses using 3-wire and/or 4-wire
implementations). Each bus can utilize RS-422, RS-485, or CAN
standards. Also, each bus is configured to provide addressability
such that the displacement sensors S can be uniquely identified.
This allows the system control panel 102 to uniquely identify and
automatically discover the displacement sensors S on the safety and
security network 110.
The analytics system 210 receives the magnetic field strength
measurements from the system control panel 102 either locally or
remotely. In FIG. 1, the analytics system 210 is implemented
remotely with respect to the system control panel 102. In this
example, the system control panel 102 directs the magnetic field
strength measurements to a public network 140 via its network
interface 130. The analytics system 210 then remotely receives the
detected magnetic field strength measurements from the public
network 140. For this example, the analytics system 210 can be
implemented as a cloud-based system. In FIG. 2, the analytics
system 210 is implemented locally by integrating the analytics
system 210 into the system control panel 102. For this example, the
analytics system 210 can be implemented as a sub-system or module
within the system control panel 102 or as a process or thread that
runs on the panel microprocessor.
The analytics system 210 determines a status of each magnetic
displacement sensor system 240 based on the received magnetic field
strength measurements. Specifically, the analytics system 210
determines the status for each magnetic displacement sensor system
240 based on a comparison of the detected magnetic field strength
measurements with at least one profile (e.g., monitoring and
looking for predictable patterns between the detected magnetic
field strength measurements and the profile). By comparing
patterns, the analytics system 210 can determine, for example,
whether a change in magnetic field strength is normal as well as
determine a magnetic field strength threshold needed to decrease a
likelihood of a false alarm. Thus, the analytics system's
determinations can be used to make the necessary dynamic
adjustments based to reduce false alarms.
The security system 100 typically includes motion detectors 118 and
addressable notification devices 124 installed on the safety and
security network 110. The motion detectors 118 generate motion data
by sensing motion and then sending the motion data to the system
control panel 102. The system control panel 102 can determine if an
intrusion occurs based on the motion data. The system control panel
102 activates the addressable notification devices 124 (e.g.,
speakers, strobes, and/or strobe/speaker combo devices) for
alerting occupants of alarm conditions such as intrusion, potential
fire, etc.
FIG. 3A schematically depicts the internal components of the
displacement sensor S in relation to the magnet M installed on the
door 112/window 113.
The displacement sensor S includes a magnetometer 150 for detecting
the magnetic field strength. In one example, the magnetometer 150
is a single axis magnetometer that detects a magnitude of the
magnetic field strength along one axis. In another example, the
magnetometer 150 is a 2-axis magnetometer that detects magnetic
field strength 2-dimensionally along two axes (e.g., x-axis and
y-axis). In another example, the magnetometer 150 is a 3-axis
magnetometer that detects magnetic field strength 3-dimensionally
along the x-axis, the y-axis, and a z-axis. The magnetometer 150
sends data (i.e., magnetic field strength measurements) via a data
pin SDA and receives power at a positive supply voltage pin
Vdd.
The displacement sensor S has a sensor controller 138 for
identifying events based on the magnetic field strength samples or
measurements and directing communication of these events.
Initially, the sensor controller 138 reads the magnetic field
strength measurements from the magnetometer 150. The sensor
controller 138 preferably includes a ring buffer or similar set of
data storage registers 139 for storing these recently read magnetic
field strength measurements over time. This buffer can contain 5 to
10 or more of the most recently read magnetic field strength
measurements, with new measurements overwriting the oldest
measurements. The sensor controller 138 can identify the events by
determining if the stored magnetic field strength measurements
indicate an event such as an open door or closed door. In one
example, the buffer stores readings over the previous period. Such
period can be less than 1 second in one example. In other examples,
it can be more than 1 second or even more than 10 seconds.
Additionally, the magnetic field measurements are often taken at
intervals of less than 500 milliseconds. In some examples, the
magnetic field measurements are taken at intervals of less than 100
milliseconds.
When the sensor controller 138 determines that an event has
occurred, the contents of the ring buffer are sent (including
respective magnetic field strength measurements) to the system
control panel 102 (where the ring buffer contents are received by
the bus master 106) via the safety and security network 110 as
event data. The sensor controller 138 is preferably a
microprocessor (e.g., ASIC microprocessor or FPGA microprocessor).
In one example, the sensor controller 138 can be integrated with
the magnetometer 150 on a single chip.
The displacement sensor S has a RS-422/RS-485/CAN wire interface 13
for receiving power and sending/receiving communication in
examples. The RS-422/RS-485/CAN wire interface 132 can receive
power from the system control panel 102 via the safety and security
network 110. The RS-422/RS-485/CAN wire interface 132 can direct
the received power to a sensor power bus that distributes power
between the magnetometer 150 and the sensor controller 138. The
RS-422/RS-485/CAN wire interface 132 can also direct communication
received from the safety and security network 110 to the sensor
controller 138 and direct communication (e.g., magnetic field
strength measurements) from the sensor controller 138 to the safety
and security network 110.
FIG. 3A illustrates the displacement sensor S in use during an
opening event for the door 112/window 113. As the door 112/window
113 is opened, the magnet M is moved away from the displacement
sensor S causing the displacement sensor S to detect a decrease in
the magnetic field strength.
FIG. 3B is nearly identical to FIG. 3A except the displacement
sensor S communicates wirelessly with the system control panel 102
via the safety and security network 110. In this example
embodiment, the RS-422/RS-485/CAN wire interface 132 is replaced
with a wireless interface 133 that wirelessly connects with the
system control panel 102 via the safety and security network 110.
Specifically, the wireless interface 133 communicates with the
safety and security network 110 via an access point 137 (e.g.,
using Bluetooth Zigbee or WiFi communications protocols, for
example). For this example, the displacement sensor S is supplied
powered from a battery 136 and a parasitic power-harvesting circuit
134. Specifically, the parasitic power-harvesting circuit 134
supplies power to be stored in the battery 136. Then, the battery
136 directs power to the sensor power bus for distribution between
the magnetometer 150, the sensor controller 138, and the wireless
interface 133. As appreciated by one of skill in the art, other
power arrangements may be implemented in order to power the
different components of the displacement sensor S.
FIG. 4 schematically depicts the internal components of the
magnetometer 150. In this example, the magnetometer 150 is the
3-axis magnetometer which includes a detection stage 151, a MUX
(multiplexer) 152, an ADC (analog-digital converter) 154, and a
signal processor 156. The detection stage 151 includes x, y, and z
detectors Dx, Dy, Dz that detect the magnetic field strength along
the x-axis, the y-axis, and the z-axis, respectively. The MUX 152,
ADS 154, and then the signal processor 156 process the detected
magnetic field strength measurements. The sensor controller 138
receives the processed magnetic field strength measurements from
the signal processor 156 via the data pin SDA. The magnetometer 150
is powered (from the sensor power bus) at the positive supply
voltage pin Vdd of the signal processor 156.
FIGS. 5A-5B are example plots of the detected magnetic field
strength (T) vs. time (seconds) along the x-axis, the y-axis, and
the z-axis for the 3-axis magnetometer for an event. These plots
represent opening/closing events for a door and specifically, the
event data contents of the ring buffer that are sent to the control
panel. FIG. 5A is an opening event when the door is opened
(decreasing magnetic field strength over time for x-axis and
y-axis) and FIG. 5B is a closing event when the door is closed
(increasing magnetic field strength over time for x-axis and
y-axis). These plots represent an example of event data that is
transmitted by the displacement sensors S to the system control
panel 102.
FIGS. 6A-6B are example plots of a magnitude of magnetic field
strength (T) vs, time (seconds) for the single axis magnetometer.
Similar to FIGS. 5A-5B, these plots represent opening/closing
events for the door and specifically, the event data contents of
the ring buffer that are sent to the control panel. FIG. 6A is an
opening event when the door is opened (decreasing magnetic field
strength over time) and FIG. 5B is a closing event when the door is
closed (increasing magnetic field strength over time).
FIG. 7 is a detailed view of the internal components of the
analytics system 210.
The analytics system 210 includes an analytics database 222 for
storing multiple clients 224 such as clients A, B, C, D, and E.
Each client 224 includes one or more window profiles WP1, WP2, WP3
. . . WP# or door profiles DP1, DP2, DP3 . . . DP# or other
profiles associated with other monitored things. Each window
profile WP# or door profile DP# corresponds with one of the windows
113 or doors 112, respectively, in one example.
The window profiles WP# and door profiles DP# include one or more
event profiles EP.sub.X (e.g., normalized event profile
EP.sub.norm, fast opening event profile EP.sub.open fast, fast
closing event profile EP.sub.close fast, slow opening event profile
EP.sub.open slow, slow closing event profile EP.sub.close slow,
secured state event profile EP.sub.secured, unsecured state event
profile EP.sub.unsecured, etc.). The normalized event profile
EP.sub.norm represents an average of the detected magnetic field
strength event data for the door 112/window 113. The time axis has
been normalized to a common time scale so that it can be used to
assess both fast and slow events. The fast opening event profile
EP.sub.open fast is a magnetic field strength event data when the
door 112/window 113 is opened quickly. The fast closing event
profile EP.sub.close fast is a magnetic field strength event data
when the door 112/window 113 is closed quickly. The slow opening
event profile EP.sub.open slow is a magnetic field strength event
data when the door 112/window 113 is opened slowly. The slow
closing event profile EP.sub.close slow is a magnetic field
strength event data when the door 112/window 113 is closed slowly.
The secured state event profile EP.sub.secured is a magnetic field
strength plot when the door 112/window 113 is in a closed stated
(e.g., door 112 is secured to the door frame 207). The unsecured
state event profile EP.sub.unsecured is a magnetic field strength
plot when the door 112/window 113 is in an open state (e.g., door
112 is not secured to the door frame 207).
The analytics system 210 includes an analytics engine 220. The
analytics engine 220 analyzes the opening/closing events received
from the displacement sensors S. Based on this analysis, the
analytics engine 220 can generate new event profiles EPx or update
current event profiles EPx. The analytics engine can also generate
new clients 224 and new window/door profiles WP#/DP# based on
receipt of events from a new displacement sensor S for a new door
or new window.
FIG. 8A is a flow chart illustrating a method of using the
displacement sensor S to indicate the opening/closing events and
then forward these events to the system control panel 102.
Initially, in step 300, the sensor controller 138 reads detected
current magnetic field strength measurements (T.sub.x,y,z) from the
magnetometer 150. The reading occurs periodically, at intervals of
usually less than a 1 second, preferably less than 500 milliseconds
or even less than 100 milliseconds. The sensor controller 138
stores the current magnetic field strength measurements
T.sub.x,y,z) in the ring buffer 139 (step 302). Usually the ring
buffer stores measurements from the previous 1 second or longer to
10 seconds or more. In step 304, the sensor controller 138
determines whether the ring buffer 139 indicates an opening/closing
event. This indication can be accomplished, for example, by
comparing the stored current magnetic field strength measurements
(T.sub.x,y,z) against generic magnetic field strengths for the
secured and/or unsecured states (e.g., magnetic field strength
thresholds) that relate to a door/window opening or closing. If no
opening/closing event is identified, step 300 is repeated. If the
opening/closing event is identified, the sensor controller 138
sends the opening/closing event (including event data such as
T.sub.x,y,z(t) measurements) to the control panel 102 and then to
the analytics system 210 or directly to the analytics system 210
(step 306).
FIG. 8B is a flow chart illustrating a method of training the
analytics system 210 based on receipt of the magnetic field
strength measurements (T.sub.x,y,z(t)) (i.e., event data) from one
of the displacement sensors S. In step 400, the analytics system
210 receives the opening/closing event (including T.sub.x,y,z(t)
measurements) from the displacement sensor S. The analytics system
210 determines a type of event: opening or closing (step 402). In
step 404, the analytics system 210 discards the event data if
atypical. Then, in step 406, the analytics system 210 reads the
door/window profile (DPn or WPn) for the door/window corresponding
with received opening/closing event. If necessary, the analytics
system 210 normalizes a time axis for the event profiles EPx
corresponding with the door/window (step 408). In step 410, the
analytics system 210 dynamically updates the event profiles (e.g.,
EP.sub.norm, EP.sub.open fast, EP.sub.close fast, EP.sub.open slow,
EP.sub.close slow, EP.sub.secured, EP.sub.unsecured, etc.) based on
the received opening/closing event. The analytics system 210 stores
the updated door/window profile (e.g., DPn or WPn) in one of the
clients 224 (e.g., client A) which is stored in the analytics
database 222.
FIG. 8C is a flow chart illustrating a method of operating the
analytics system 210. In step 500, the analytics system 210
receives the opening/closing event data including T.sub.x,y,z(t)
measurements from the displacement sensor S. The analytics system
210 determines a type of event: opening or closing (step 502). In
step 504, the analytics system 210 reads the door/window profile
(DPn or WPn) for the door/window corresponding with received
opening/closing event. The analytics system 210 compares the
opening/closing event data to event profiles EPx (e.g.,
EP.sub.norm, EP.sub.open fast, EP.sub.close fast, EP.sub.open slow,
EP.sub.close slow, EP.sub.secured, EP.sub.unsecured, etc.) of the
corresponding door/window profile (e.g., WP1 or DP1) (step 506). In
step 508, the analytics system 210 determines whether this
comparison is indicative of a normal status, a damaged sensor
status, a disconnected sensor status, a predictive failure status
(i.e., the operation of the sensor appear to be eroding over time),
etc. For example, the analytics system 210 can determine whether a
pattern associated with the opening/closing event matches an
expected pattern of the event profile EPx. If there is a match, the
analytics system 210 determines that the status is normal (i.e.,
normal status). If there is not a match, the analytics system can
determine whether the differences between patterns correspond to
the damaged sensor status, the disconnected sensor status, or a
sensor that might fail (predictive failure status), for
example.
In step 510, the analytics system 210 then generates a diagnostic
assessment based on this determination (step 510). This diagnostic
assessment of the magnetic displacement sensor system 240 over time
allows for improved nuisance/false alarm management fir the
magnetic displacement sensor system 240. The analytics system 210
sends the diagnostic assessment to the system control panel 102
(step 512). The system control panel 102 notifies users of
necessary repairs/replacements based on the diagnostic
assessment.
The diagnostic assessment can include a variety of information
related to the status of the magnetic displacement sensor system
240. For example, the diagnostic assessment can include information
on a distance between the magnet M and the displacement sensor S as
determined from the detected magnetic field strength. Also, for
example, the diagnostic assessment can include information on the
comparison between opening/closing events and event profile EPx
such as whether the magnetic field strength of the event is
sufficiently high compared to the expected magnetic field strength
of the event profile EPx. In another example, the diagnostic
assessment can include information on whether the displacement
sensor S has shown any intermittent weakening in its ability to
detect the magnetic field from the magnet M. Other information
related to the status of the of the magnetic displacement sensor
system 240 can be included in the diagnostic assessment as
appreciated by one of skill in the art.
While this invention has been particularly shown and described with
references to preferred embodiments thereof, it will be understood
by those skilled in the art that various changes in form and
details may be made therein without departing from the scope of the
invention encompassed by the appended claims.
* * * * *
References